Conventionally, since a CT photographing device in dental treatment needs a large amount of image data, CT tomographic images are obtained using a two-dimensional sensor having a generally large detecting area. On the other hand, a panoramic photographing device can obtain panoramic tomographic images using a CCD (Charge Coupled Device) sensor having a relatively small rectangular detecting area.
Also, in an X-ray photographing device which can obtain CT tomographic images and panoramic tomographic images by switching between a CT photographing and a panoramic photographing in order to enhance convenience, a two-dimensional sensor having a large detecting area is used (see Patent Literature 1).